The present invention relates generally to an encoding method of and an encoding apparatus for performing high-efficiency encoding on digital signals such as digital audio data, an encoded data decoding method of and an encoded data decoding apparatus for decoding data encoded by high-efficiency encoding, a transmission method of and a transmission apparatus for transmitting data encoded by high-efficiency encoding, a sub information attaching method of and a sub information attaching apparatus for attaching sub information to data encoded by high-efficiency encoding, a recording medium in which data encoded by high-efficiency encoding are recorded, a data distribution system for distributing data encoded by high-efficiency encoding, and a terminal apparatus for and a distribution center for use in this data distribution system.
Several methods are known for obtaining audio data such as music. One of them is to purchase recording media themselves. These media are phonograph records and CDs (Compact Disks) for example. In another known method, desired audio data in received broadcast programs are recorded on recording media.
Recently, a method based on a server system is also known in which large quantities of audio data (music data (music information)) are stored in on a hard disk for example and customers transfer the music data from the hard disk to their external recording media.
In the above-mentioned server-system based method, each server is installed at the store for example. A customer goes to the store with his own recording medium (external recording medium), pays a predetermined amount of money, and records desired music data from the server system to the recording medium, thereby realizing the purchase of music. The above-mentioned server installed at the store is generally called a kiosk terminal or a content vending machine.
Generally, the music data stored in a server system are compressed in consideration of the storage capacity and transfer capacity for example of the server system. Therefore, the server system is adapted to transfer and record demanded music data to the medium of a customer (purchaser) in a time shorter than the actual play time of that music data.
For the selection of music data to be purchased, each customer enters the sub information such as the title, player, and play time of the music into the server system in the form of text or image. The server system is adapted to allow each customer to check these entries, so that the customer can simply select desired music data, record the selected music data to his own recording medium, and use the recorded music data as desired.
Generally, the above-mentioned server system is compatible with external recording media of plural types. For example, customers can record music data to a small-size magneto-optical disk such as an MD (MiniDisc) (trademark) and a semiconductor device such as a memory card.
Sometimes, it occurs that the music data recorded to an MD for example from the server system are recorded again to another medium a memory card for example, because of the unavailableness of an MD player for example. In this case, the user may not copy the music data from his own predetermined recording medium to another recording medium of his own due to the problems of copyright or deterioration of tone quality for example.
If this happens, the customer must newly purchase from the server system the music data which are compatible with another recording medium (or a new recording medium). However, this brings the customer a disadvantage that the same music data must be purchased again while the recording medium in which these music data have been stored is used no longer.
In the case where, with the same recording medium, music data with the compression with enhanced tone quality as compared with the compression at a previous purchase are purchased, the customer has to pay for the music data again. In this case, too, it brings the customer a disadvantage that same music data must be purchased again even if the recording medium in which these music data of lower music quality have been stored is used no longer.
If, for example, a recording medium is defective and therefore it is necessary to record the same music data to another recording medium, these music data must be purchased from a server system for plural times.
One of the methods proposed for solving the above-mentioned problems is to record the identification information of the generation source (purchase destination) of music data purchased before and, when purchasing the same music data again from the original purchase destination, the repurchasing of the same music data from the original purchase destination is made free of charge or at a lower cost than that at the initial purchase. However, this method is impracticable because related-art recording media have no area in which to record information about the generation source (purchase destination) of music data.
Consequently, the applicant hereof disclosed, in a patent application (Japanese Patent Laid-open No. 2001-56469, a method of and apparatus for determining whether or not the generation source of the music data recorded on a recording medium is a predetermined distributor by use of the identity of the encoded data formed by a high-efficiency encoding apparatus.
The above-mentioned disclosed method and apparatus are based on the following points. Namely, the encoded data (binary data) which are high-efficiency encoded by the predetermined high-efficiency encoding apparatus remain unchanged when the encoded data are recorded as they are. However, for the same music data, if high-efficiency encoding apparatuses for encoding the data are different from one another, the encoded data (binary data) formed by high-efficiency encoding completely differ from one another due to the difference between encoding processing timings for example.
By use of this difference, matching is performed between the high-efficiency encoded data (binary data) to determine whether these data have been encoded by the same encoding apparatus in the same timed relation, thereby making it possible to determine whether the particular encoded data have been provided by a particular music data distributing server system.
However, in the case of the above-mentioned disclosed method and apparatus, whether or not the music data distributed so as to be recorded to a recording medium of a customer have been provided by a same server system (device) can be surely and easily determined but, if different providers (business entities) distribute music data by use of a same server system (device), the customer of particular music data to be distributed to a recording medium of a purchaser cannot be identified.
In this case, the term the same server system includes both cases in which two or more providers distribute music data through one server system and two or more different providers distribute music data by use of identical server systems manufactured by one manufacturer.
Consequently, new services such as the movement of music data between recording media and the upgrading of the compression processing of music data cannot be provided by each different provider of the music data.
The number of providers of music data is expected to increase in the future and therefore it is required to surely and easily determine which provider has distributed particular music data through a server system, thereby making it possible to provide various new services by different providers.